Calender stack



A. T. HURTER CALENDER STACK Oct. 27, 1964 5 Sheets-Sheet 1 Filed April 15 1965 1 7 I14, 6 II/\/ /A o o o 1 6 O O O O O O O INVENTOR Alfred T. HUR TER jeflirstanm yk & Gr.

A TTORNE YS A. T. HURTER CALENDER STACK Oct. 27, 1964 5 Sheets-Sheet 2 Filed April 15, 1963 FIG. 2

INVENTOR Alfred T. HURTER fzc/LmzzymA 6a.

ATTORNEYS United States Patent 3,154,008 CALENDER STACK Alfred T. Hurter, Mount Royal, Quebec, Canada, assignor to Dominion Engineering Works Limited, Montreal,

Quebec, Canada Filed Apr. 15, 1963, Ser. No. 272,887 Claims priority, application Canada Feb. 9, 1963 Claims. (Cl. 100-162) This invention relates to calender stacks and more particularly to calender stacks embodying an improved arrangement for the relief of calender roll nip-pressures, for use in the paper making and other industries, for calendering material in sheet, web or strip form.

It will be understood that although this invention specifically describes a calender stack as used in the paper making industry, the principles and features described herein may be employed in calenders designed for use in the textile, plastic and other industries, where relief of calender roll nip-pressures is an important factor.

In the paper making industry the development of wider paper making machines and correspondingly wider calenders, has resulted in the use of longer, larger diameter and thus heavier calender rolls. This use of heavier calender rolls has resulted in increased nip-pressures between the rolls to the extent where the nip-pressures are excessive and tend to crush the paper. It has thus become increasingly necessary to devise various means for decreasing these excessive nip-pressures.

The conventional arrangements for decreasing calender roll nip-pressures employ mechanical, hydraulic or pneumatic means for applying upward lifting forces to the calender roll bearing housings.

A disadvantage with these conventional arrangements is that the upward lifting forces applied to the ends of the rolls cause deflections, which are diflicult to compensate by normal roll crowning operations.

Another disadvantage lies in the necessity for compli cated mechanisms and piping layouts, which are required to produce the upward lifting forces on the ends of the rolls.

In its basic form, this invention overcomes the above mentioned disadvantages by providing a calender structure in which the calender rolls are arranged in a line extending at an angle to the vertical, such that part of the dead weight of each roll is supported by the frame structure, thus reducing the nip-pressures between the rolls due to the dead weight of the rolls, as compared with a conventional calender stack where the calender rolls are arranged in a vertical line and the resulting nippressures are due to the total dead weight of the rolls. As an example, with the calender rolls arranged in a line inclined at 45 to the vertical, the resulting nip-pressures between the rolls would be 70.7% of the nip-pressures for a similar calender with rolls arranged in a vertical line. In the following specification, this invention is described as embodied in a calender stack in which the calender rolls are mounted on frame members which are pivotally mounted, on the calender fixed frame structure, to swing from a vertical position to a position inclined to the vertical, thus providing a range of calender roll nippressures, from a maximum when the rolls extend in a vertical line, to a minimum when the line of rolls is at the maximum angle of inclination to the vertical.

Another advantage inherent in this invention is that, when the calender rolls are in a line inclined to the vertical, there is a component of roll weight at right angles to the line of the calender rolls, which loads the hearings in a manner which off-sets any tendency towards vibration of the rolls and assists in the prevention of roll barring.

A further advantage of this invention is that, the thread- 3,15%,bii8 Patented @ct. 27, 1954 ing of the tail of a sheet of paper between the adjacent stacks of a double inclined calender stack arrangement, is simplified.

Conventional methods of threading the tail of a sheet of paper between adjacent stacks of conventional double calenders involves the provision of guide means and air jets, to induce the tail to follow a fixed course.

A disadvantage in this conventional method when applied to conventional vertical double calender stacks is that, the length of pass between the lower nip of the first stack to the upper nip of the second stack is very large, thus necessitating very long guide means and complicated air jet arrangements.

This disadvantage is overcome in the present invention by providing an arrangement of double calender stacks in which the line of calender rolls in each stack is inclined to the vertical, thus providing a shorter distance between the lower nip of the first inclined stack and the upper nip of the second inclined stack and allowing for the provision of shorter guide means and simplified air jet arrangements, resulting in a more efficient and more positive tail threading operation.

It is, therefore, the main object of this invention to provide a calender in which the calender rolls are arranged in a line inclined to the vertical, in which position, part of the dead weight of the rolls is transferred to the calender frame structure and a reduction of the nip pressures between the rolls is effected.

Another object of the invention is to provide a calender in which the calender rolls are arranged in a line and are supported on a frame structure which is movable to allow for variation of the angle of inclination of the line of rolls and thus provide a means for varying the reduction of nip-pressures between the rolls.

Another object of the invention is to provide a calender in which the barring of calender rolls is reduced.

A further object is to provide a calender in which the threading of the tail of a sheet of paper between adjacent stacks of a double inclined calender stack arrangement is simplified and made more positive, by reducing the length of the pass.

These and other objects of this invention will be apparent from the following detailed specification and the accompanying drawings, in which:

FIG. 1 is a side view of a calender embodying the present invention and showing the calender rolls arranged in a vertical line.

FIG. 2 is a front view of the calender shown in FIG. 1.

FIG. 3 is a view similar to FIG. 1, but showing the line of calender rolls arranged at an angle to the vertical.

FIG. 4 is a sectional view, taken in the direction of 44- in FIG. 3 and showing drive means for varying the angle of inclination of the line of rolls and for moving the roll supporting frame members in unison.

With reference now to the figures, calender rolls 11 are journalled in bearings and housings 12 which are pivotally supported on pivots 13 mounted on movable frame members 14. Movable frame members 14 are pivotally mounted at the upper ends thereof on pivots 15 in sliding head members 16 and at the lower ends thereof on pivots 17 in sliding base members 18.

Bottom roll 19 is journalled in bearings and housings 2t} mounted on sliding base members 18 and sliding base members 18 are slidably mounted for horizontal movement on base frame structure 2]..

Sliding head members 16 are slidably mounted for vertical movement in the upper calender frame structures 22, which are positioned on the upper portions of fixed calender vertical frame structures 23. Fixed calender vertical frame structures 23 are mounted at the lower ends thereof on base frame structures 21 and tied at the upper ends thereof by cross-member 24.

rolls.

Reference now to FIG. 4 and also to F168. 1 and 3, shows an arrangement for varying the angle of inclination of movable frame members 14, and for releasably securing movable frame members 14 in any position to which they are moved. It will be understood, however, that the arrangement shown and described herein is but one execution of a means for providing the required movement of movable frame members 14 and that other conventional means may be used, such as, hydraulic cylinders, etc.

In the execution shown, worm means 25 and screw means 26 interconnect movable frame members 14 and fixed vertical frame structures 23, with worm means 25 positioned on the lower portions of fixed vertical frame structures 23 and screw means 26 attached to the ends of sliding base members 18.

Worm and screw means 25' and 26 respectively are positioned at each side of the calender and are interconnected to move in unison by cross-shaft 27.

Drive motor 28 is connected, through a gear unit 29, to provide reversible rotation to one of the worm means 25. The reversible rotation may be provided by either a reversible drive motor 28 or a reversible gear unit 29.

When the calender is in the position where the line of calender rolls 11 extends vertically, the calender is operable as a conventional calender in which the nip-pressures between the rolls are due to the total weight of the When it is desired to decrease the nip-pressures, worm means 25 are rotated through drive motor 28 and cross-shaft 27, to cause screw means 26 to extend and move sliding base members 13 horizontally away from fixed vertical frame structures 23.

This will result in movable frame members 14, and the line of calender rolls 11 which are attached thereto, assuming a position inclined to the vertical, in which position part of the dead weight of each roll is supported by the movable frame members 14, with a consequent reduction in nip-pressures.

Reversing the worm means 25 will result in the retraction of screw means 26, causing the line of calender rolls 11 to assume a line less inclined to the vertical, with a consequent increase in nip-pressures.

Sliding base members 18 may be bolted down to base frame structures 21, to provide additional structural security during periods between variations in the angle of inclination of the line of calender rolls.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A calender including a roll carrying frame structure mounted to swing about a horizontal pivotal axis, a series of calender rolls journalled in said frame structure so that each roll is supported on the next lower roll in nip pressure contact therewith and means for swinging said frame structure about said pivotal axis to various positions of inclination to vary the effective nip pressures between the rolls by transferring a portion of the dead weight of the rolls to the frame structure.

2. A calender as set forth in claim 1, in which said horizontal pivotal axis is located at or adjacent the lower end of said frame structure.

3. A calender as set forth in claim 1, in which said horizontal pivotal axis is located at or adjacent the upper end of said frame structure.

4. A calender as set forth in claim 1, in which said frame structure is mounted to swing about horizontal pivotal axes located at or adjacent the upper and lower ends of said frame structure.

5. A calender includin a fixed frame structure, a roll carrying movable frame structure mounted to swing about horizontal pivotal axes located at or adjacent the upper and lower ends of said frame structure, a series of calender rolls pivotally mounted on said movable frame struc hire one above the other, and worm and screw means interconnecting said fixed frame structure and said movable frame structure and arranged to swing said movable frame structure to different positions of adjustment about said pivotal axes and for securing said movable frame structure in any selected position of adjustment.

6. A calender as set forth in claim 5, in which said movable frame structure comprises two frame members, one of said frame members being positioned at each side of the calender and mounted to swing about horizontal pivotal axes located at or adjacent the upper and lower ends of said frame members and means for swinging said frame members in unison.

7. A calender including a fixed frame structure, roll carrying frame members positioned at each side of the calender and mounted to swing about horizontal pivotal axes, a series of calender rolls pivotally mounted on said frame members one above the other, worm and screw means interconnecting said fixed frame structures and said frame members and arranged to swing said frame members to different positions of adjustment about said pivotal axes and for securing said frame members in any selected position of adjustment and cross-shaft means interconnecting said frame members for swinging said frame members in unison.

8. A calender including a fixed frame structure, roll carrying frame members positioned at each side of the calender and mounted to swing about horizontal pivotal axes located at or adjacent the upper and lower ends of said frame members, a series of calender rolls journalled on said frame members one above the other, head members mounted for vertical movement in the upper portions of said fixed frame structure and arranged to pivotally support the upper pivotal axes of said frame members, base members mounted for horizontal movement in the lower portions of said fixed frame structure and arranged to pivotally support the lower pivotal axes of said frame members, worm and screw means interconnecting said fixed frame structure and said base members and arranged to swing said frame members to different positions of adjustment about said pivotal axes and for securing said frame members in any selected position of adjustment and cross-shaft means interconnecting said frame members for swinging said frame members in unison.

9. A roll calender comprising a generally vertically extending roll carrying frame, a series of superimposed calender rolls carried by said frame and arranged so that each roll is supported by the next lower roll in nip pressure contact therewith, and means for swinging said frame about a horizontal pivotal axis to regulate the nip pressures by transferring more or less of the dead weight of each roll from the next lower roll to the frame or vice versa.

10. A roll calender as set forth in claim 9, in which the rolls are connected to the frame so that each roll is shifted laterally with respect to the next lower roll as the frame is swung to different positions about said pivotal axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,068,539 Stanton July 29, 1913 1,925,972 Standley et al Sept. 5, 1933 2,985,100 Hornbostel May 23, 1961 3,044,440 Molsberry et a1 July 17, 1962 FOREIGN PATENTS 202,753 Great Britain Aug. 30, 1923 

9. A ROLL CALENDER COMPRISING A GENERALLY VERTICALLY EXTENDING ROLL CARRYING FRAME, A SERIES OF SUPERIMPOSED CALENDER ROLLS CARRIED BY SAID FRAME AND ARRANGED SO THAT EACH ROLL IS SUPPORTED BY THE NEXT LOWER ROLL IN NIP PRESSURE CONTACT THEREWITH, AND MEANS FOR SWINGING SAID FRAME ABOUT A HORIZONTAL PIVOTAL AXIS TO REGULATE THE NIP PRESSURES BY TRANSFERRING MORE OR LESS OF THE DEAD WEIGHT OF EACH ROLL FROM THE NEXT LOWER ROLL TO THE FRAME OR VICE VERSA. 